I recently finished a book called 50 Reasons People Give for Believing in a God by Guy P. Harrison.
The book is focused: it systematically goes through the top 50 reasons people give for believing in a god, and it carefully explains why a skeptic finds these reasons severely lacking. It also argues that the believer himself should find these reasons lacking, as well.
The author has gone through great pains to keep the book respectful yet direct.
I could tell that the author had spent a bit of time actually interacting with believers in an attempt to figure what they believe and why. There are a number of tactics that you hit upon from the number of interactions. He happened to use or recommend an approach similar to a few of the tactics that I have written about, and a few that I have plans to write about.
One of my favorite tactics is to ask for the best example of whatever claim a theist is making. He mentioned this as a response when you get a claim like, "Hundreds of prophecies were fulfilled by Jesus..." Ask, "what is the most impressive prophecy that Jesus fulfilled?" You interact with the best case that the theist can give, you aren't trying to defend from a shotgun blast of verses and prophecies, and often the person has not seriously thought about any of the prophecies.
On a side note, I heard a street preacher use the same tactic to devastating effect when a skeptic listening was talking about how much the words of the Bible had changed and how the message has been distorted over the years. The preacher said, "That's a fair enough objection. What message specifically has been changed? Or what is the most blatant verse change that you are thinking about?"
It stopped the skeptic cold because he only had some nebulous idea about how the Bible was changed, and no idea about any of the specifics.
To finish my book review, I'd say that the book was worth the time spent reading it. It feels a bit repetitive in that he continues to make the point that there is no good reason to think that X is true; or to rely on faulty reasoning Y. I also really appreciate the effort he makes to emphasize the reasons people give to believe in all kinds of gods (not just the Big God). It's all true, and he explains very carefully exactly what mistakes are being made.
In the end, I recommend the book, especially if you intend on engaging religious people. It gives you a good feel for what you will encounter, and demonstrates a tactful way of critically engaging them.